If there’s a characteristic that’s common among proponents of alternative medicine, it’s tenacity. The willingness to stick with an idea, no matter the evidence, must give one a certain clarity. The naturalistic fallacy is often the foundation. Natural is good, synthetic is bad, no matter the evidence. In some cases, in spite of the evidence. How one deals with contradictory evidence is an effective tool to differentiate between medicine and alternative medicine – given sufficient convincing evidence, medicine changes its practices. The same can’t be said for alternative medicine, where few treatments are ever discarded. Otherwise practices like homeopathy, acupuncture, reiki, and chiropractic would have disappeared long ago. It’s also why disproven products continue to have occasional resurgences in interest. Cranberry is one. It has been touted as a treatment and a preventative for urinary tract infections for years. And it doesn’t seem to work – not well, and not reliably, if you look at all the trials. And that’s being generous, considering the poor quality of the evidence with its inherent biases. I know a dead parrot when I see one. Yet its advocates, mainly manufacturers (is there a Big Cran?) keep insisting it’s alive, supported by the occasionalpositive report that appears. With a new systematic review and meta-analysis that declares it’s effective, it’s time to update our review. (more…)